1. Field
The following description relates to a semiconductor, and more particularly, to an organic semiconductor transistor.
2. Description of Related Art
Organic semiconductor transistors, which are thin film transistors including channel layers formed of organic semiconductor materials, are attracting attention. Since the organic thin film transistors can be formed to be lightweight and flexible, the organic thin film transistors are expected to be applied to next generation displays which have high impact resistance and portability. The organic thin film transistor can be used as a semiconductor by applying a soluble low-molecular organic semiconductor and a polymer organic semiconductor thereon. Since a large area process can be applied using a printing method, it can be expected that a cost thereof is significantly reduced. Since the organic semiconductor can be formed at a low temperature, the organic semiconductor has an advantage in that a flexible substrate, such as a plastic substrate, can be used.
Such an organic semiconductor transistor includes an organic semiconductor pattern, which forms a channel layer, and a source electrode and a drain electrode which are formed of metals to be connected to the organic semiconductor pattern. However, due to a high contact resistance between the organic semiconductor material and the source electrode and the drain electrode, the performance of an organic electronic element has a limitation. In order to reduce the limitation, there is a method of doping an organic semiconductor region with dopant molecules to reduce a contact resistance so as to reduce the limitation.
However, since, in the conventional doping method of reducing a contact resistance, doping is performed on usually a surface of an upper layer of an organic semiconductor thin film, there is a limitation in that the conventional doping method is used for usually an organic transistor having a top-gate structure in which an organic semiconductor layer is disposed on a substrate and a gate insulator film and a gate electrode are sequentially disposed on the organic semiconductor layer.